i did a session today with a vocalist in florida (i'm in new york).
we used 'cleanfeed', which worked nicely (i have no affiliation with them).
i used two pc's on my end, one for cleanfeed and one for ableton. one tricky bit is that the remote signal can't be routed through the master (it would be completely distracting on the remote side).
cleanfeed's latency varied between 70 and 100 msec. it would be much nicer if it could be set to a fixed value, even say 200msec, so that each loop captured could be automatically lined up with delay compensation.
even so, it's pretty easy to drag each loop's content forward to match the track.
it was pretty easy to create a song, working 4 measures or so at a time. the sound quality is quite acceptable.
another nice bit is that the artist on the other end need not be tech-savvy. we used cleanfeed's free accounts.